Salt filtration system and method of removing a radioactive material from a gas using the same

Abstract

A method of removing a radioactive material from a gas includes directing the gas through a bed of salt, wherein the gas includes water vapor and the radioactive material. The salt constitutes more than 50 percent by weight of the bed. The method additionally includes condensing the water vapor in the bed and dissolving a portion of the salt to form a salt solution. The method further includes absorbing the radioactive material into the salt solution while a remainder of the gas passes through the bed. A salt filtration system configured to perform the method may be implemented as a pre-filter (or post-filter) to an existing filter unit or as a standalone filter.

The invention claimed is: 
     
       1. A method of removing a radioactive material from a gas, comprising:
 directing the gas through a bed of salt, the gas including water vapor and the radioactive material, the salt constituting more than 50 percent by weight of the bed, the salt including sodium pentaborate; 
 condensing the water vapor in the bed and dissolving a portion of the salt to form a salt solution; and 
 absorbing the radioactive material into the salt solution while a remainder of the gas passes through the bed. 
 
     
     
       2. The method of  claim 1 , wherein the directing includes a venting of the gas from a reactor containment during an accident at a nuclear plant. 
     
     
       3. The method of  claim 1 , wherein the radioactive material and the salt include an element in common. 
     
     
       4. The method of  claim 1 , wherein the salt further includes at least one of a cesium salt and an iodine salt. 
     
     
       5. The method of  claim 1 , wherein the salt includes at least 50 percent by weight of the sodium pentaborate. 
     
     
       6. The method of  claim 1 , wherein the radioactive material is at least one of cesium and iodine. 
     
     
       7. The method of  claim 1 , wherein the dissolving involves an endothermic reaction, a heat of solution of the endothermic reaction being provided by the gas such that a temperature of the gas is lowered by the endothermic reaction. 
     
     
       8. The method of  claim 1 , wherein the absorbing includes capturing the radioactive material via polar bonding. 
     
     
       9. The method of  claim 1 , wherein the decontamination factor is at least 100.